News: construction is now underway on a memorial to extinct species of the present and future, designed by David Adjaye for the Isle of Portland, England.

A ground-breaking ceremony took place last week for the Mass Extinction Memorial Observatory (MEMO), a 30-metre-high stone spiral that will house an information and exhibition centre for the 860 species identified as extinct since the demise of the dodo in the 17th century.

Perched on the edge of a cliff, the £30 million building will also contain an observatory overlooking Bowers Quarry, one of the main producers of Portland Stone since the late eighteenth century – prompting Adjaye's decision to build in stone.

"A fitting insertion into the landscape, the project presents an opportunity to revitalise the old Bowers Quarry and to draw attention back to the natural beauty and craftsmanship of Portland," said Adjaye Associates in a statement.

"Rather than a building or shelter, MEMO is devised as a journey, exploring the relationship between interior and exterior, landscape and enclosure."

An image representing every extinct species will be carved into the walls, with space left to add more carved stones for future extinctions. A bell inside the building will toll to mark these occasions.

Adjaye designed the observatory and exhibition centre as a gift to the MEMO charitable organisation, which is collaborating with the EO Wilson Biodiversity Foundation in the US.